The following relates generally to memory systems and more specifically to a source follower-based sensing scheme.
Memory devices are widely used to store information in various electronic devices such as computers, wireless communication devices, cameras, digital displays, and the like. Information is stored by programming different states of a memory device. For example, binary memory devices have two logic states, often denoted by a logic “1” or a logic “0”. In other memory devices, more than two logic states may be stored. To access the stored information, a component of the electronic device may read, or sense, the stored logic state in the memory device. To store information, a component of the electronic device may write, or program, the logic state in the memory device.
Various types of memory devices exist, including those that employ magnetic hard disks, random access memory (RAM), read only memory (ROM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), flash memory, phase change memory (PCM), and others. Memory devices may be volatile or non-volatile. Non-volatile memory, such as PCM and FeRAM, may maintain stored logic states for extended periods of time even in the absence of an external power source. Volatile memory devices, such as DRAM, may lose stored logic states over time unless they are periodically refreshed by a power source.
A device may determine the logic states stored in memory by comparing the signals output by memory cells with a reference signal. For example, a sense amplifier may be used to sense the difference between a voltage of the memory cell and a reference voltage. But the circuit that provides the memory cell voltage and the reference voltage to the sense amplifier may introduce delay into the sensing scheme (e.g., by providing the voltages serially) and may consume excess power (e.g., by requiring an external bias current). Thus, the circuit may increase the latency and power consumption associated with sensing, which may negatively impact the device's performance, among other disadvantages.